Bizjournals -- Metro Atlanta’s 20 Steak ’n Shake restaurants will roll back prices on steakburgers to 15 cents on Friday to celebrate the chain’s 75th anniversary. On Feb. 13 from 8 a.m. to 11 a.m., individual steakburgers are 15 cents, the same price the burgers were when the chain started in Normal, Ill., in 1934. And after 11, the price will rise to only 75 cent and stay that way until March 29.